In a process for producing acrylic acid or methacrylic acid (hereinafter referred to as (meth)acrylic acid) by catalytic vapor-phase oxidation and in a process for producing a (meth)acrylic ester by direct esterification, various high-boiling matters generate in individual step units such as a dehydration column, distillation column, acetic acid separation column, high-boiling-matter cracking reactor (high-boiling-matter cracking column), and the like. In general, these high-boiling matters are temporarily stored in tanks and thereafter subjected to a treatment such as recovery treatment, incineration disposal, or landfill disposal. Some kinds of high-boiling matters are stored in tanks via a high-boiling-matter cracking reactor. For storage, tanks disposed respectively for separate production processes have been used because the high-boiling matters are yielded from a variety of sources and have properties characteristic of the individual processes.
Such a storage method heretofore in use is intended to avoid a trouble that when high-boiling matters generating in individual processes are mixed, then the polymerization inhibitor, by-product polymers, and the like contained therein precipitate. This is because the polymers precipitated adhere as a tacky ingredient to the inside of an apparatus to arouse troubles. This necessitates separate tanks for high-boiling matters in plant construction. There has hence been a problem that the construction cost is high and the area necessary for tank installation is large.